feat(frontend): add API client, layout, and routing

- Create Axios-based API client with sources, jobs, and dashboard endpoints
- Add responsive Layout component with navigation sidebar
- Set up React Router with Dashboard, Backups, and Settings routes
- Configure TanStack Query provider with default options
- Use lucide-react for navigation icons

frontend/node_modules/lucide-react/dist/esm/icons/computer.js

@@ -0,0 +1,18 @@
+/**
+ * @license lucide-react v0.303.0 - ISC
+ *
+ * This source code is licensed under the ISC license.
+ * See the LICENSE file in the root directory of this source tree.
+ */
+
+import createLucideIcon from '../createLucideIcon.js';
+
+const Computer = createLucideIcon("Computer", [
+  ["rect", { width: "14", height: "8", x: "5", y: "2", rx: "2", key: "wc9tft" }],
+  ["rect", { width: "20", height: "8", x: "2", y: "14", rx: "2", key: "w68u3i" }],
+  ["path", { d: "M6 18h2", key: "rwmk9e" }],
+  ["path", { d: "M12 18h6", key: "aqd8w3" }]
+]);
+
+export { Computer as default };
+//# sourceMappingURL=computer.js.map